Functionalized polyfluorenes for use in optoelectronic devices

ABSTRACT

The present invention relates to process comprising reacting a polyfluorenes comprising at least one structural group of formula I 
     
       
         
         
             
             
         
       
     
     with an iridium (III) compound of formula II 
     
       
         
         
             
             
         
       
     
     The invention also relates to the polyfluorenes, which are products of the reaction, and the use of the polyfluorenes in optoelectronic devices.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

This invention was made with Government support under contract numberDOE NETL DE-FC26-05NT42343 awarded by the U.S. Department of Energy. TheGovernment may have certain rights in the invention.

BACKGROUND

Organic light emitting devices (OLEDs), which make use of thin filmorganic materials that emit light when subjected to a voltage bias, areexpected to become an increasingly popular form of flat panel displaytechnology. Potential applications include cellphones, personal digitalassistants (PDAs), computer displays, informational displays invehicles, television monitors, as well as light sources for generalillumination. Due to their bright colors, wide viewing angle,compatibility with full motion video, broad temperature ranges, thin andconformable form factor, low power requirements and the potential forlow cost manufacturing processes, OLEDs are seen as a future replacementtechnology for cathode ray tubes (CRTs) and liquid crystal displays(LCDs). Due to their high luminous efficiencies, OLEDs may replaceincandescent, and perhaps even fluorescent, lamps for certain types ofapplications.

Light emission from OLEDs typically occurs via electrofluorescence, i.e.light emission from a singlet-excited state formed by applying a voltagebias across a ground state electroluminescent material. It is believedthat OLEDs capable of producing light by an alternate mechanism,electrophosphorescence, i.e. light emission from a triplet excited stateformed by applying a voltage bias across a ground stateelectrofluorescecent material, will exhibit substantially higher quantumefficiencies than OLEDs that produce light primarily byelectrofluorescence. Light emission from OLEDs by electrophosphorescenceis limited since the triplet excited states in most light emittingorganic materials are strongly disposed to non-radiative relaxation tothe ground state. Thus, electrophosphorescent materials hold promise askey components of OLED devices and other optoelectronic devicesexhibiting greater efficiencies relative to the current state of theart. For example, OLEDs capable of light production byelectrophosphorescence are expected to exhibit a reduction (relative toOLEDs which produce light primarily by electrofluorescence) in theamount of energy lost to radiationless decay processes within the devicethereby providing an additional measure of temperature control duringoperation of the OLED.

Improved light emission efficiencies have been achieved by incorporatinga phosphorescent platinum-containing dye in an organicelectroluminescent device such as an OLED (Baldo et al., “HighlyEfficient Phosphorescent Emission from Organic ElectroluminescentDevices”, Nature, vol. 395,151-154,1998) and phosphorescentiridium-containing dyes have also been employed (U.S. 2003/0096138).Polymerizable phosphorescent iridium complexes based on a ketopyrroleligand are disclosed in pending U.S. application Ser. No. 11/504,552,filed on 14 Aug. 2006, which claims priority from U.S. provisionalapplication Ser. No. 60/833,935, filed on 28 Jul. 2006, the entirecontents of which are incorporated by reference in their entirety.

Notwithstanding earlier developments, there is currently considerableinterest in finding novel phosphorescent materials, which increaseefficiency and provide for a greater measure of control of the color oflight produced by an OLED, while achieving improved lifetime of thedevices.

BRIEF DESCRIPTION

In one aspect, the present invention relates to process comprisingreacting a polyfluorenes comprising at least one structural group offormula I

with an iridium (III) compound of formula II

wherein

R¹ and R² are independently alkyl, substituted alkyl, aryl, substitutedaryl or a combination thereof;

R⁵ is H or CHO;

R³ and R⁴ are independently hydrogen, alkyl, substituted alkyl, aryl,substituted aryl or a combination thereof;

R¹¹ and R¹² taken together form a substituted or unsubstitutedmonocyclic or bicyclic heteroaromatic ring;

R¹³ is independently at each occurrence halo, nitro, hydroxy, amino,alkyl, aryl, arylalkyl, alkoxy, substituted alkoxy, substituted alkyl,substituted aryl, or substituted arylalkyl;

Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof;

X is selected from a direct bond, alky, substituted alkyl, andcombinations thereof;

Y is CHO or NH₂;

Z is CHO or NH₂ where Z does not equal Y; and

p is 0, 1 or 2.

In another aspect, the present invention relates to polyfluorenes thatmay be prepared by the process of the present invention. Thepolyfluorenes include at least one structural group of formula V

wherein

R⁶ is a group of formula VI

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof; and

R¹¹ and R¹² taken together form a substituted or unsubstitutedmonocyclic or bicyclic heteroaromatic ring;

R¹³ is independently at each occurrence halo, nitro, hydroxy, amino,alkyl, aryl, arylalkyl, alkoxy, substituted alkoxy, substituted alkyl,substituted aryl, or substituted arylalkyl;

Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof;

W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or a combination thereof;

X′ is selected from a direct bond, alkylene, substituted alkylene, orcombinations thereof;

Y′ is alkylene, substituted alkylene, arylene, substituted arylene,oxaalkylene, substituted oxaalkylene, or a combination thereof;

X″ is alkylidene, substituted alkylidene, or a combination thereof;

Y″ is alkylidene, substituted alkylidene, arylidene, substitutedarylidene, or a combination thereof, and

p is 0, 1 or 2.

In another aspect of the present invention relates to organicoptoelectronic devices having at least one layer comprising apolyfluorene having at least one structural group of formula V.

DESCRIPTION OF FIGURES

FIG. 1 shows the ¹H NMR spectra (500 MHz) of polyfluorenes with pendantaldehyde substituents through reaction with primary amines andsubsequent reduction.

DETAILED DESCRIPTION

To more clearly and concisely describe and point out the subject matterof the claimed invention, the following definitions are provided forspecific terms, which are used in the following description and theappended claims.

“Aryl” and “heteroaryl” mean a 5- or 6-membered aromatic orheteroaromatic ring containing 0-3 heteroatoms selected from nitrogen,oxygen or sulfur; a bicyclic 9- or 10-membered aromatic orheteroaromatic ring system containing 0-3 heteroatoms selected fromnitrogen, oxygen or sulfur; or a tricyclic 13- or 14-membered aromaticor heteroaromatic ring system containing 0-3 heteroatoms selected fromnitrogen, oxygen or sulfur. The aromatic 6- to 14-membered carbocyclicrings include, for example, benzene, naphthalene, indane, tetralin, andfluorene; and the 5- to 10-membered aromatic heterocyclic rings include,e.g., imidazole, pyridine, indole, thiophene, benzopyranone, thiazole,furan, benzimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine,pyrazine, tetrazole and pyrazole. Arylene refers to a radical that isbivalent and formed by removal of hydrogen from two carbon sites on anaromatic nucleus. Arylidene refers to an alkylidene unit substitutedwith an aryl group.

“Arylalkyl” means an alkyl residue attached to an aryl ring. Examplesare benzyl and phenethyl. Heteroarylalkyl means an alkyl residueattached to a heteroaryl ring. Examples include pyridinylmethyl andpyrimidinylethyl. Alkylaryl means an aryl residue having one or morealkyl groups attached thereto. Examples are tolyl and mesityl.

“Alkoxy” or “alkoxyl” refers to groups of from 1 to 8 carbon atoms of astraight, branched, cyclic configuration and combinations thereofattached to the parent structure through an oxygen. Examples includemethoxy, ethoxy, propoxy, isopropoxy, cyclopropyloxy, and cyclohexyloxy.Lower alkoxy refers to groups containing one to four carbons.

“Acyl” refers to groups of from 1 to 8 carbon atoms of a straight,branched, cyclic configuration, saturated, unsaturated and aromatic andcombinations thereof, attached to the parent structure through acarbonyl functionality. One or more carbons in the acyl residue may bereplaced by nitrogen, oxygen or sulfur as long as the point ofattachment to the parent remains at the carbonyl. Examples includeacetyl, benzoyl, propionyl, isobutyryl, t-butoxycarbonyl, andbenzyloxycarbonyl. Lower-acyl refers to groups containing one to fourcarbons.

“Heterocyclic” means a cycloalkyl or aryl residue in which one to two ofthe carbons are replaced by a heteroatom such as oxygen, nitrogen orsulfur. Examples of heterocycles that fall within the scope of theinvention include pyrrolidine, pyrazole, pyrrole, indole, quinoline,isoquinoline, tetrahydroisoquinoline, benzofuran, benzodioxan,benzodioxole (commonly referred to as methylenedioxyphenyl, whenoccurring as a substituent), tetrazole, morpholine, thiazole, pyridine,pyridazine, pyrimidine, thiophene, furan, oxazole, oxazoline, isoxazole,dioxane, and tetrahydrofuran.

“Substituted” refers to residues, including, but not limited to, alkyl,alkylaryl, aryl, arylalkyl, and heteroaryl, wherein up to three H atomsof the residue are replaced with lower alkyl, substituted alkyl, aryl,substituted aryl, haloalkyl, alkoxy, carbonyl, carboxy, carboxalkoxy,carboxamido, acyloxy, amidino, nitro, halo, hydroxy, OCH(COOH)₂, cyano,primary amino, secondary amino, acylamino, alkylthio, sulfoxide,sulfone, phenyl, benzyl, phenoxy, benzyloxy, heteroaryl, orheteroaryloxy.

“Haloalkyl” refers to an alkyl residue, wherein halogen atoms replaceone or more hydrogen atoms; the term haloalkyl includes perhaloalkyl.Examples of haloalkyl groups that fall within the scope of the inventioninclude CH₂F, CHF₂, and CF₃.

“Oxaalkyl” refers to an alkyl residue in which one or more carbons havebeen replaced by oxygen. It is attached to the parent structure throughan alkyl residue. Examples include methoxypropoxy, 3,6,9-trioxadecyl andthe like. The term oxaalkyl refers to compounds in which the oxygen isbonded via a single bond to its adjacent atoms (forming ether bonds); itdoes not refer to doubly bonded oxygen, as would be found in carbonylgroups. Similarly, thiaalkyl and azaalkyl refer to alkyl residues inwhich one or more carbons has been replaced by sulfur or nitrogen,respectively. Examples include ethylaminoethyl and methylthiopropyl.

Many of the compounds described herein may contain one or moreasymmetric centers and may thus give rise to enantiomers, diastereomers,and other stereoisomeric forms that may be defined, in terms of absolutestereochemistry, as (R)— or (S)—. The present invention is meant toinclude all such possible isomers, as well as, their racemic andoptically pure forms. Optically active (R)— and (S)— isomers may beprepared using chiral synthons or chiral reagents, or resolved usingconventional techniques. When the compounds described herein containolefinic double bonds or other centers of geometric asymmetry, andunless specified otherwise, it is intended that the compounds includeboth E and Z geometric isomers. Likewise, all tautomeric forms are alsointended to be included.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values, which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate

These are only examples of what is specifically intended and allpossible combinations of numerical values between the lowest value andthe highest value enumerated are to be considered to be expressly statedin this application in a similar manner.

In one aspect, the present invention related to a process of making apolyfluorene by imine condensation of a pendant aldehyde group locatedon a polyfluorene backbone with a primary amine followed by reduction.Dynamic covalent chemistry may be employed in the initial imine bondformation; imine bond formation is a reversible thermodynamic reaction.Subsequent reduction of the imine to the corresponding amine provides anamine-functionalized polyfluorene.

In particular embodiments, the process involves an imine condensationreaction of a polyfluorene containing structural units of formula I andone or more iridium (III) compounds of formula II.

Iridium (III) compounds of formula II suitable for attaching through anamine group have been described in U.S. patent application Ser. No.11/504,871, filed 16 Aug. 2006, Ser. No. 11/506,002, filed 17 Aug. 2006,U.S. Ser. No. 1/506,001, filed 17 Aug. 2006, Ser. No. 11/507,051, filed18 Aug. 2006, Ser. No. 11/599,972, filed 15 Nov. 2006, Ser. No.11/637,582, filed 12 Dec. 2006, Ser. No. 11/504,552, filed 14 Aug. 2006,Ser. No. 11/504,870 filed 16 Aug. 2006, Ser. No. 11/504,084 filed 14Aug. 2006, all of which claim priority from U.S. Provisional ApplicationSer. No. 60/833,935, filed 28 Jul. 2006. The entire contents of theabove patent applications are incorporated herein by reference. Theiridium (III) compounds contain an additional emissive element, tripletemitting Iridium (III) complexes with ancillary pyrrole ligands.

In certain embodiments R¹ of formula I may be an oxaalkylene,substituted oxaalkylene, and combinations thereof. In certainembodiments R¹ is

In still other embodiments, R¹¹ and R¹² of formula II, taken togetherform a substituted or unsubstituted isoquinoline.

The imine condensation between the polyfluorene and the one or moreiridium (III) compounds may occur simultaneously or sequentially.Reduction of the resulting imine occurs using a reducing agent, such assodium borohydride (NaBH₄).

In certain embodiments, the process further involves the reaction of thepolyfluorene of formula I with one more triarylamines. In particular thetriarylamine may be a compound of formula III

wherein

R′ and R′″ are independently hydrogen, alkyl, substituted alkyl,alkenyl, alkynyl, substituted alkenyl, substituted alkynyl, alkyloxy,substituted alkoxy, alkenoxy, alkynoxy, substituted alkenoxy,substituted alkynoxy, taken together a heterocyclic ring or acombination thereof;

Ar⁶ and Ar⁷ are independently aryl, heteroaryl, substituted aryl,substituted heteroaryl, or a combination thereof;

R′ is an alkyl, substituted alkyl, alkenyl, alkynyl, substitutedalkenyl, substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy,alkynoxy, substituted alkenoxy, substituted alkynoxy, or a combinationthereof; m is an integer from 0 to 10;

n is an integer from 0 to 4; and

Y is CHO or NH₂ and does not equal Z of formula 1.

In certain embodiments R′ and R′″ of the compound of formula III arehydrogen, and m is equal to 0.

In other embodiments, the triarylamine may be a compound of formula IV

wherein

R′ is an alkyl, substituted alkyl, alkenyl, alkynyl, substitutedalkenyl, substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy,alkynoxy, substituted alkenoxy, substituted alkynoxy, or a combinationthereof;

m is an integer from 0 to 10;

n is an integer from 0 to 4; and

Y is CHO or NH₂ and does not equal Z of formula I.

In certain embodiments, m and n of formula IV are equal to 0.

The imine condensation between the polyfluorene, the one or more iridium(III) compounds, and the one or more triarylamines may occursimultaneously, such that the iridium (III) compound and thetriarylamine are added in a single step to the polyfluorene, orsequentially such that the iridium (III) compound and triarylamine areadded in separate steps to the polyfluorene. Reduction of the resultingimine occurs using a reducing agent, such as sodium borohydride (NaBH4).The reduction step may also occur simultaneously or sequentially.

More particularly, the process may result in a polyfluorenes wherein theweight percentage of a iridium (III) compound containing group to atriarylamine containing group may be from about 0.5 to about 50 mol %.This provides a polymer with both the triarylamine and the iridium III)compound in the polymer backbone and allows attenuation of the emissiveand transport properties of the polyfluorene material.

Suitable triarylamines are described in U.S. Pat. No. 5,728,801, U.S.Pat. No. 5,929,194, U.S. Pat. No. 5,948,552, U.S. Pat. No. 6,309,763,U.S. Pat. No. 6,605,373, U.S. Pat. No. 6,900,285, WO 2004/060970, WO2005/049546 and WO 2005/052027, to Dow Global Technologies, the entirecontents of which are incorporated by reference

Polyfluorenes for use in the processes of the present invention mayinclude structural units in addition to those of formula I, such asunsubstituted fluorenyl units and/or fluorenyl units substituted withsaturated groups such as alkyl. Other structural units may be derivedfrom conjugated compounds as described in U.S. Pat. No. 6,900,285. Inparticular, structural units derived from tertiary aromatic amines maybe used as described in U.S. Pat. Nos. 5,948,552, 6,605,373, and6,916,902. The amount of structural units derived from unsaturatedmonomers ranges from about 0.05 mol % to about 50 mol %, particularlyfrom about 1 mol % to about 25 mol %, and more particularly from about 1mol % to about 10 mol %.

The polyfluorenes may be prepared by methods known in the art for makingpolyfluorenes, including Suzuki coupling of the appropriate dihalide anddiboronate/diboronic acid and Yamamoto coupling. U.S. Pat. Nos.5,708,130; 6,169,163; 6,512,083; and 6,900,285 describe synthesis ofpolymers containing fluorene subunits.

In one aspect, the present invention relates to a polyfluorene producedby a method of imine condensation of a pendant aldehyde group located ona polyfluorene backbone with a primary amine followed by reduction. Inanother aspect, the present invention relates to a polyfluorenesproduced by a method of imine condensation of a pendant primary aminegroup located on a polyfluorenes backbone with an aldehyde followed byreduction. In both aspects, Dynamic covalent chemistry may be employedin the initial imine bond formation; imine bond formation is areversible thermodynamic reaction. Subsequent reduction of the imine tothe corresponding amine provides an amine-functionalized polyfluorene.

In particular embodiments, the polyfluorene thus formed comprises atleast one structural group of formula V.

Iridium (III) compounds suitable for attaching to the polyfluorenesthrough a secondary amino group have been described in U.S. patentapplication Ser. No. 11/504,871, filed 16 Aug. 2006, Ser. No.11/506,002, filed 17 Aug. 2006, Ser. No. 1/506,001, filed 17 Aug. 2006,Ser. No. 11/507,051, filed 18 Aug. 2006, Ser. No. 11/599,972, filed 15Nov. 2006, Ser. No. 11/637,582, filed 12 Dec. 2006, Ser. No. 11/504,552,filed 14 Aug. 2006, Ser. No. 11/504,870 filed 16 Aug. 2006, Ser. No.11/504,084 filed 14 Aug. 2006, all of which claim priority from U.S.Provisional Application Ser. No. 60/833,935, filed 28 Jul. 2006. Theentire contents of the above patent applications are incorporated hereinby reference. The iridium (III) compounds contain an additional emissiveelement, triplet emitting Iridium (III) complexes with ancillary pyrroleligands.

In certain embodiments, Y′ is oxaalkylene, substituted oxaalkylene, or acombination thereof. In certain embodiments, Y′ is

In still other embodiments, R¹¹ and R¹² of the iridium (III) compound offormula VI, when taken together, may form a substituted or unsubstitutedisoquinoline.

Polyfluorenes of the present invention may additionally comprise atleast one triarylamine substituted group. In particular embodiments, thegroup is a compound of formula VII

wherein

R″ and R′″ are independently hydrogen, alkyl, substituted alkyl,alkenyl, alkynyl, substituted alkenyl, substituted alkynyl, alkyloxy,substituted alkoxy, alkenoxy, alkynoxy, substituted alkenoxy,substituted alkynoxy, taken together a heterocyclic ring or acombination thereof;

Ar⁶ and Ar⁷ are independently aryl, heteroaryl, substituted aryl,substituted heteroaryl, or a combination thereof;

R′ is an alkyl, substituted alkyl, alkenyl, alkynyl, substitutedalkenyl, substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy,alkynoxy, substituted alkenoxy, substituted alkynoxy, or a combinationthereof;

W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or a combination thereof;

X′ is selected from a direct bond, alkylene, substituted alkylene, orcombinations thereof;

Y′ is alkylene, substituted alkylene, arylene, substituted arylene,oxaalkylene, substituted oxaalkylene, or a combination thereof;

X″ is alkylidene, substituted alkylidene, or a combination thereof;

Y″ is alkylidene, substituted alkylidene, arylidene, substitutedarylidene, or a combination thereof, and

n is an integer from 0 to 4.

In certain embodiments R³ and R⁴ of formula V are hydrogen and n is 0.In certain embodiments, the triarylamine is connected to thepolyfluorene according to Formula VII where Y′ is oxaalkylene,substituted oxaalkylene, and combinations thereof. In certainembodiments Y′ is

In particular embodiments the R⁶ group of formula V additionallyincludes at least one triarylamine substituted group of formula VIII

wherein

R′ is an alkyl, substituted alkyl, alkenyl, alkynyl, substitutedalkenyl, substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy,alkynoxy, substituted alkenoxy, substituted alkynoxy, or a combinationthereof;

W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or a combination thereof;

X′ is selected from a direct bond, alkylene, substituted alkylene, orcombinations thereof;

Y′ is alkylene, substituted alkylene, arylene, substituted arylene,oxaalkylene, substituted oxaalkylene, or a combination thereof;

X″ is alkylidene, substituted alkylidene, or a combination thereof;

Y″ is alkylidene, substituted alkylidene, arylidene, substitutedarylidene, or a combination thereof, and

n is an integer from 0 to 4.

In certain embodiments R³ and R⁴ of formula V are hydrogen. In certainother embodiments, the triarylamine is connected to the polyfluoreneaccording to Formula VIII where Y′ is an oxaalkylene, substitutedoxaalkylene, and combinations thereof. In certain embodiments Y′ is

In the polyfluorenes of the present invention, the weight percentage ofan iridium (III) compound to a triarylamine substituted secondary aminemay be from about 0.5 to about 50 mol %. This provides a polymer withboth the triaryl amine and the iridium (III) compound in the polymerbackbone and allows attenuation of the emissive and transport propertiesof the polyfluorene material.

In certain embodiments the polyfluorene may further containunsubstituted fluorenyl units and/or fluorenyl units substituted withsaturated groups such as alkyl. Other structural units may be derivedfrom conjugated compounds as described in U.S. Pat. No. 6,900,285. Inparticular, structural units derived from tertiary aromatic amines maybe used as described in U.S. Pat. Nos. 5,948,552, 6,605,373, and6,916,902. The amount of structural units derived from unsaturatedmonomers ranges from about 0.05 mol % to about 50 mol %, particularlyfrom about 1 mol % to about 25 mol %, and more particularly from about 1mol % to about 10 mol %.

The polyfluorenes may be prepared by methods known in the art for makingpolyfluorenes, including Suzuki coupling of the appropriate dihalide anddiboronate/diboronic acid and Yamamoto coupling. U.S. Pat. Nos.5,708,130; 6,169,163; 6,512,083; and 6,900,285 describe synthesis ofpolymers containing fluorene subunits.

In a preferred embodiment the polyfluorenes may comprise structuralunits of formula IX

wherein

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof;

R¹¹ and R¹² taken together form a substituted or unsubstitutedmonocyclic or bicyclic heteroaromatic ring;

R¹³ is independently at each occurrence halo, nitro, hydroxy, amino,alkyl, aryl, arylalkyl, alkoxy, substituted alkoxy, substituted alkyl,substituted aryl, or substituted arylalkyl; and

Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof.

In certain embodiments, the polyfluorenes may further comprisingstructural units of formula X

wherein

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof;

R¹¹ and R¹² taken together form a substituted or unsubstitutedmonocyclic or bicyclic heteroaromatic ring;

R¹³ is independently at each occurrence halo, nitro, hydroxy, amino,alkyl, aryl, arylalkyl, alkoxy, substituted alkoxy, substituted alkyl,substituted aryl, or substituted arylalkyl; and

Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof.

In certain embodiments, the polyfluorenes may further comprisingstructural units of formula XI

wherein

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof; and

R¹⁴ and R¹⁵ are independently hydrogen, alkyl, substituted alkyl andcombinations thereof.

In another embodiment the polyfluorenes may further comprisingstructural units of formula XII

wherein

R³, R⁴ and R⁹ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof.

In another aspect, the invention relates to optoelectronic devicescontaining the functionalized polyfluorenes in one or more lightemissive layers. The polyfluorene of Formula I may be blended withfluorescent emitting materials such as (co)polymers based on fluorenemonomers, for example, F8-TFB, commercially available emissive polymerssuch as ADS131BE, ADS231BE, ADS331BE, ADS431BE, ADS429BE, ADS160BE,ADS329BE, ADS229BE, ADS129BE, ADS180BE, supplier by American DyeSources, and BP105 and BP361, available from Sumation Company Ltd. Othermaterials useful for blending with the polymers of the present inventioninclude molecular and oligomeric species such as fluorene trimers andtheir derivatives, polymeric or molecular triarylamine materials,including those described in U.S. Pat. Nos. 3,265,496 and 4,539,507, andcommercially available triarylamines available from American DyeSources, such as ADS254BE, ADS12HTM, and ADS04HTM, substitutedpolyphenylene polymers, such ADS120BE from American Dye Sources, andpolymers having oligomeric units connected via non-conjugated linkinggroups, as described in U.S. 2005/0256290.

It is preferable that when blending the functionalized polyfluorenes ofthe present invention with other materials, that the lowest tripletenergy level of the other materials (as measured by photoluminescence orother technique) be greater that the triplet energy of the pendentIridium-based emitter of the polymers of the present invention. Inparticular, polymers may be blended with one or more fluorescentmaterials such as blue-emitting fluorene (co)polymers, as thesetypically have a lowest triplet energy below that of the lowest emissivesingle energy of the polymers of the present invention and exhibit blueemission.

The functionalized polyfluorenes of the present invention and/or blendsof the amine-functionalized polyfluorenes with blue-emitting fluorene(co)polymers may be contained in a light emitting layer of the devicedisposed adjacent to another light emitting layer containing one or morefluorene polymers or copolymers such as BP105 or F8-TFB to form anbilayer structure. In these devices, the bilayer structure may be formedby via several different means, as described in PCT/U.S.07/68620. Forexample, following deposition of the first layer, the bilayer may beinsolublized via a thermal treatment alone, or via the inclusion withinthe first layer of a cross-linkable polymerization agent to link thepolymer chains together or form an interpenetrating network. Thepolymerization may be initiated via UV irradiation or thermalactivation. The polymerization processing may be enhanced through theaddition of a small amount of an initiator such as IRGACURE® 754, theESACURE® initiators from Sartomer, BPO, or AIBN. Alternatively, thelayer structure may be formed by applying the second layer from asolvent that does not dissolve the first layer, through contactlamination (Ramsdale et al. J. Appl. Phys, vol 92, pg. 4266 (2002)), orthrough vapor deposition. If desired, these methods maybe appliedserially to produce a multilayer structure in which one or more of thelayers includes one or more of the polymers of the present invention.

Optoelectronic device according to the present invention mayadditionally include at least one photoluminescent (“PL”) materialoptically coupled with the polymer such that the phosphor materialabsorbs a portion of EM radiation emitted thereby and emits EM radiationin a third wavelength range. Materials for use as the PL material andexemplary device structures containing PL materials are described inU.S. Pat. No. 7,063,900, the entire contents of which are incorporatedby reference.

An opto-electronic device, exemplified by an organic light emittingdevice, typically contains multiple layers which include, in thesimplest case, an anode layer and a corresponding cathode layer with anorganic electroluminescent layer disposed between said anode and saidcathode. When a voltage bias is applied across the electrodes, electronsare injected by the cathode into the electroluminescent layer whileelectrons are removed from (or “holes” are “injected” into) theelectroluminescent layer from the anode. Light emission occurs as holescombine with electrons within the electroluminescent layer to formsinglet or triplet excitons, light emission occurring as singletexcitons transfer energy to the environment by radiative decay. Tripletexcitons, unlike singlet excitons, typically cannot undergo radiativedecay and hence do not emit light except at very low temperatures.Theoretical considerations dictate that triplet excitons are formedabout three times as often as singlet excitons. Thus the formation oftriplet excitons, represents a fundamental limitation on efficiency inorganic light emitting devices which are typically operated at or nearambient temperature. Polymers according to the present invention mayserve as precursors to light emissive, short-lived excited state speciesthat form as the normally unproductive triplet excitons encounter andthat transfer energy.

Other components, which may be present in an organic light-emittingdevice in addition to the anode, cathode and light emitting material,include hole injection layers, electron injection layers, and electrontransport layers. During operation of an organic light-emitting devicecomprising an electron transport layer, the majority of charge carriers(i.e. holes and electrons) present in the electron transport layer areelectrons and light emission can occur through recombination of holesand electrons present in the electron transport layer. Additionalcomponents, which may be present in an organic light-emitting device,include hole transport layers, hole transporting emission (emitting)layers, hole blocking layers and electron transporting emission(emitting) layers.

The organic electroluminescent layer is a layer within an organic lightemitting device which when in operation contains a significantconcentration of both electrons and holes and provides sites for excitonformation and light emission. A hole injection layer is a layer usuallyin contact with the anode, which promotes the injection of holes fromthe anode into the interior layers of the OLED; and an electroninjection layer is a layer usually in contact with the cathode thatpromotes the injection of electrons from the cathode into the OLED.Neither the hole injection layer nor the electron transport layer neednot be in contact with the cathode. Frequently the electron transportlayer is not an efficient hole transporter and thus it serves to blockholes migrating toward the cathode. An electron transport layer is alayer, which facilitates conduction of electrons from cathode to acharge recombination site. A hole transport layer is a layer which whenthe OLED is in operation facilitates conduction of holes from the anodeto charge recombination sites and which need not be in contact with theanode. A hole transporting emission layer is a layer in which when theOLED is in operation facilitates the conduction of holes to chargerecombination sites, and in which the majority of charge carriers areholes, and in which emission occurs not only through recombination withresidual electrons, but also through the transfer of energy from acharge recombination zone elsewhere in the device. A electrontransporting emission layer is a layer in which when the OLED is inoperation facilitates the conduction of electrons to chargerecombination sites, and in which the majority of charge carriers areelectrons, and in which emission occurs not only through recombinationwith residual holes, but also through the transfer of energy from acharge recombination zone elsewhere in the device.

Materials suitable for use as the anode include materials having a bulkconductivity of at least about 100 ohms per square inch, as measured bya four-point probe technique. Indium tin oxide (ITO) is frequently usedas the anode because it is substantially transparent to lighttransmission and thus facilitates the escape of light emitted fromelectro-active organic layer. Other materials, which may be utilized asthe anode layer, include tin oxide, indium oxide, zinc oxide, indiumzinc oxide, zinc indium tin oxide, antimony oxide, and mixtures thereof.

Materials suitable for use as the cathode include zero valent metals,which can inject negative charge carriers (electrons) into the innerlayer(s) of the OLED. Various zero valent metals suitable for use as thecathode include K, Li, Na, Cs, Mg, Ca, Sr, Ba, Al, Ag, Au, In, Sn, Zn,Zr, Sc, Y, elements of the lanthanide series, alloys thereof, andmixtures thereof. Suitable alloy materials for use as the cathode layerinclude Ag—Mg, Al—Li, In—Mg, Al—Ca, and Al—Au alloys. Layered non-alloystructures may also be employed in the cathode, such as a thin layer ofa metal such as calcium, or a metal fluoride, such as LiF, covered by athicker layer of a zero valent metal, such as aluminum or silver. Inparticular, the cathode may be composed of a single zero valent metal,and especially of aluminum metal.

Materials suitable for use in hole injection layers include3,4-ethylenedioxythiophene (PEDOT) and blends of PEDOT with polystyrenesulfonate (PSS), commercially available from H.C. Stark, Inc. under theBAYTRON® tradename, and polymers based on a thieno[3,4b]thiophene (TT)monomer, commercially available from Air Products Corporation.

Materials suitable for use in hole transporting layers include1,1-bis((di-4-tolylamino)phenyl)cyclohexane,N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-(1,1′-(3,3′-dimethyl)biphenyl)-4,4′-diamine,tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine,phenyl-4-N,N-diphenylaminostyrene, p-(diethylamino)benzaldehydediphenylhydrazone, triphenylamine,1-phenyl-3-(p-(diethylamino)styryl)-5-(p-(diethylamino)phenyl)pyrazoline,1,2-trans-bis(9H-carbazol-9-yl)cyclobutane,N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine, copperphthalocyanine, polyvinylcarbazole, (phenylmethyl)polysilane;poly(3,4-ethylene dioxythiophene) (PEDOT), polyaniline,polyvinylcarbazole, triaryldiamine, tetraphenyldiamine, aromatictertiary amines, hydrazone derivatives, carbazole derivatives, triazolederivatives, imidazole derivatives, oxadiazole derivatives having anamino group, and polythiophenes as disclosed in U.S. Pat. No. 6,023,371.

Materials suitable for use as the electron transport layer includepoly(9,9-dioctyl fluorene), tris(8-hydroxyquinolato)aluminum (Alq3),2,9-dimethyl-4,7-diphenyl-1,1-phenanthroline,4,7-diphenyl-1,10-phenanthroline, 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole,3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole,1,3,4-oxadiazole-containing polymers, 1,3,4-triazole-containingpolymers, quinoxaline-containing polymers, and cyano-PPV.

EXAMPLES General Procedure for Preparation of Fluorene Aldehyde Monomer

A preferred synthetic route for preparing the 2,7-dibromofluorenonestarting material is described in CN 1634839 (Scheme 1). The procedureuses bromine in water and results in high conversion of fluorenone tothe desired dibromo product with little to no formation ofmono-brominated species and unknown side-products are virtually absent.These under-brominated and unknown products are typically present insubstantially higher quantities when fluorenone is brominated using amethod that employs N-bromosuccinimde in methanesulfonic acid.

After three crystallizations of a scaled-up reaction, 150 g of highquality 2,7-dibromofluorenone (>99.8% purity, LC analysis) ready to beused in subsequent reactions was obtained. A portion of the2,7-dibromofluorenone was converted into tosylated ethylene glycol9,9′-disubstituted fluorene (5) in four steps (Scheme 2).

The synthetic method described JP 1997255609 for glycosylation wasemployed with a slight modification, affording the desired fluorene 4 inhigh conversion (95%) at substantially shorter reaction times (12 hours)and under neutral conditions.

The tosylated fluorene monomers (5) may be used in the preparation ofthe fluorene aldehyde monomer 7 for investigations of post-polymermodifications employing dynamic covalent chemistry (Scheme 3).

The target pendant polyfluorene containing 37.5% of an aromatic aldehydesubstituent was prepared by the condensation of the two dibromides 7 and9 with the bis-borate ester 8 under Suzuki-catalyzed condition in thepresence of a hindered phosphine ligand PCy-Biphen (Scheme 5). Thepolyfluorene material had a significantly high molecular weight(Mw=1.04×107 and Mn=4.73×106) and a typical dispersivity (Mw/Mw=2.19)expected for a condensation polymer prepared under Suzuki conditions asassessed by gel permeation chromatography (GPC)

The viability of post-polymer modification was tested by preparing twopendant benzylamine functionalized polyfluorenes following the two-stepprocedure of (1) imine condensation followed by (2) subsequent reductionusing NaBH₄ (Scheme 5).

A sample of the parent polyfluorene material was reduced separately withNaBH₄ (Scheme 6) and used as a standard for the determination of thepercent incorporation of two different benzyl amines using ¹H NMRspectroscopy.

Investigations using ¹H NMR spectroscopy revealed that the benzylamineswere introduced at a portion of pendant sites of the polyfluorene.Closer inspection revealed that 60% (benzylamine) and 70%(4-methoxybenzylamine) of the available aromatic aldehyde substituentshad condensed with these two benzylamines and were subsequently reducedto give a mixture corresponding secondary amine and benzyl alcohol aspendant side-chains

As shown in FIG. 1 the 1H NMR spectra (500 MHz) may be used todistinguish the various products. The parent polyfluorene productcontaining pendant aldehydes is recorded in the bottom spectra (A trace,recorded in CD₂Cl₂), the fully reduced polyfluorene product containingpendant benzylalcohols is shown next (B trace, recorded in 10%MeOD/CD₂Cl₂) followed by the two polyfluorene products obtained frompost-polymeric modification employing dynamic covalent chemistry (DCC)and subsequent reductions to prepare functional polyfluorene materialsbearing benzylamine (C trace, recorded in 10% MeOD/CD₂Cl₂) and4-methoxybenzylamine (D trace, recorded in 10% MeOD/CD₂Cl₂)substituents. The symbols correspond to the methylene proton resonancefor the ethylene glycol moiety (†=ArOCH₂CH₂OAr), for the hexyloxy moiety(*=ArOCH₂CH₂CH₂CH₂CH₂CH₂), for the benzylic moiety (‡=HOCH₂PH), and forthe secondary amine region (§=ArCH₂NHCH₂Ar).

General Procedure for Preparation of Fluorene Amine Monomer

In an alternative approach for the same process described above pendantprimary amines are located on the backbone of a polyfluorene polymer andare reacted with a suitable aldehyde to give the imine intermediate.

The tosylated fluorene (5) as described in Scheme 3 can be employed toprepare the corresponding pendant amine fluorene monomers 7a and 7b.

These pendant amine substituted fluorene monomers can be subsequentlyemployed in Suzuki-based polymerizations and reacted with suitabledibromides and boronic acids to generate polyfluorene materials withpendant amine containing substituents (Scheme 8).

In a similar manner already described for polyfluorenes with pendantaldehydes, these pendant primary amine polyfluorenes can be convertedinto secondary amines by employing the two-step post-polymermodification procedure, which includes (1) imine condensation with asuitable aldehyde followed by (2) subsequent reduction using NaBH₄(Scheme 9). The aldehyde species can also be a modified Ir(III) complexas shown by the example in Scheme 10 and the like.

Experimental Example 1 Synthesis of 9-(4-Hexyloxyphenyl)-9H-fluoren-9-ol(2)

Bromo-(4-hexyloxy)-benzene was prepared by alkylation of 4-bromophenol(91.2 g, 527 mmol) with bromohexane (86.0 g, 520 mmol), K₂CO₃ (80.0 g,580 mmol) in acetone (200 mL) at reflux for 12 h. After removal thesalts by filtration, the reaction mixture was concentrated to dryness togive an oil. The oil was dissolved in EtOAc (100 mL) and transferred toa separatory funnel and washed with 5% NaOH (4×200 mL). An additional200 mL volume of EtOAc was added to the separatory funnel and thecontents were washed with NaHCO₃ (1×200 mL) and finally dried overMgSO₄. Removal of the EtOAc solvents afforded a light yellow oil and wasused without further purification. Yield: 119 g, 89%. ¹H NMR (500 MHz,CD₂Cl₂, 25° C.) δ 0.91 (t, 3H), 1.34 (m, 4H), 1.45 (m, 2H), 1.76 (m,2H), 3.92 (t, 2H), 6.79 (d, 2H), 7.36 (d, 2H). A dry 250 mL three-neckflask was charged with small Mg turnings (2.80 g, 118 mmol) followed byanhydrous THF (100 mL). A few iodine crystals were added and theheterogeneous mixture was heated at reflux for 15 min and then cooled toroom temperature. Stirring was stopped and 1,2-diromoethane (0.25 mL)was added to the reaction vessel. After 5 min elapsed an exothermicreaction ensued and stirring was resumed for 20 min. The reaction wasthen cooled to 20° C. and bromo-(4-hexyloxy)-benzene (27.8 g, 108 mmol)was added over a period of an hour while keeping the temperature between14-18° C. The cooling bath was removed and the reaction was stirred foran additional 10 min as the temperature of the reaction rose to 28° C.The reaction was cooled to room temperature and the contents weretransferred by pipette to a stirred toluene (250 mL) suspension of2,7,-dibromofluorenone (30.0 g, 90.4 mmol) that was maintained at −10°C. with a cooling bath. The cooling bath was removed and the reactionmixture was stirred at room temperature for 20 min and subsequentlytreated with 20 mL of EtOH and a saturated solution of NH₄Cl (5 mL). Thereaction mixture was filtered to remove insoluble materials andtransferred to a separatory funnel containing EtOAc (100 mL) and H₂O(100 mL). The layers were separated and the organic layer was washedwith H₂O (2×100 mL), brine (1×100 mL), and dried over MgSO₄. Thesolvents were removed to dryness to give a crude yellow solid (50.8 g).The crude material was recrystallized from Hexanes/CH₂Cl₂ to afford theproduct as an off-white microcrystalline material. Yield: 38.6 g, 79%.¹H NMR (500 MHz, CD₂Cl₂, 25° C.) δ 0.91 (t, 3H), 1.32 (m, 4H), 1.41 (m,2H), 1.74 (m, 2H), 2.66 (s, 1H), 3.92 (t, 2H), 6.79 (d, 2H), 7.23 (d,2H), 7.43 (d, 2H), 7.52 (m, 4H).

Example 2 Synthesis of9-(4-Hexyloxyphenyl)-9′-(4-hydroxyphenyl)-fluorene (3)

A CH₂Cl₂ (75 mL) solution of phenol (24 g, 256 mmol) and9-(4-hexyloxyphenyl)-9H-Fluoren-9-ol (2) (30.0 g, 55.7 mmol) was treatedwith 20 drops of methanesulfonic acid, which caused the solution tochange to purple in color. The reaction was stirred at room temperatureuntil TLC analysis indicated that the starting fluorenol was consumed.The reaction mixture was transferred to a separatory funnel and washedwith a saturated solution of NaHCO₃ (1×200 mL), H₂O (3×150 mL), and thenthe organic layer was dried over MgSO₄. The solvents were removed todryness to give an oil. The oil was adsorbed onto silica gel from aCH₂Cl₂ solution and the solvents were removed to dryness. The driedsilica gel was transferred to the top of a glass-fritted funnel (500 mL)containing a packed H₂O slurry of silica gel (200 mL) fitted on top avacuum flask. The contents of the funnel were flushed with H₂O byapplying vacuum to the flask, which eluted phenol from the silica gel.After excess phenol was removed, the product was eluted from the silicagel with CH₃CN. The solvents were removed using a rotary evaporator witha bath at 45° C., which resulted in the formation of a milky solutionfrom which a white solid formed. The product was collected byfiltration, washed with water and dried. Isolated as a mixture (96:10)of para- and ortho-isomers of the hydroxyphenol adduct. Yield: 34.0 g,98%. ¹H NMR (500 MHz, CD₂Cl₂, 25° C.) δ 0.89 (t, 3H), 1.32 (m, 4H), 1.43(m, 2H), 1.74 (m, 2H), 3.91 (t, 2H), 4.90 (s, 1H), 6.72 (d, 2H), 6.77(d, 2H), 7.01 (d, 2H), 7.04 (d, 2H), 7.47 (d, 2H), 7.50 (d, 2H), 7.63(d, 2H).

Example 3 Synthesis of9-(4-Hexyloxyphenyl)-9′-(4-(2-hydroxyethoxy)phenyl)-fluorene (4)

The phenol 3 (33.0 g, 53.7 mmol) was dissolved in xylenes (30 mL), driedover MgSO₄, and filtered. The solution was concentrated on a rotaryevaporator until the contents of the flask weighed 70 g. The xylenessolution of 3 was then placed under an inert atmosphere of N₂ andtreated with ethylene carbonate (3.9 mL, 59.0 mmol) which was thenheated at reflux for 15 h. After this time had passed, the reaction wascooled to room temperature and the solvents were removed to give ayellow oil. The oil was chromatographed through 2 L of SiO₂ and elutedwith CH₂Cl₂. The product was isolated as a colorless oil after removalof the solvents. Yield 29.1 g, 82%. ¹H NMR (500 MHz, CD₂Cl₂, 25° C.) δ0.94 (t, 3H), 1.36 (m, 4H), 1.47 (m, 2H), 1.78 (m, 2H), 2.03 (t, 1H),3.94 (m, 4H), 4.07 (t, 2H), 6.81 (d, 2H), 6.85 (d, 2H), 7.08 (d, 2H),7.11 (d, 2H), 7.52 (d, 2H), 7.54 (d, 2H), 7.67 (d, 2H).

Example 4 Synthesis of9-(4-Hexyloxyphenyl)-9′-(4-(2-p-toluenesulfonylethoxy)phenyl)-fluorene(5)

A toluene solution (200 mL) of the ethylene glycol 4 (29.1 g, 44.2 mmol)was treated with p-toluenesulfonyl chloride (13.3 g, 69.8 mmol) andtriethylamine (19.4 mL, 140 mmol) and stirred at room temperature for 60h under an inert atmosphere of N2. The reaction mixture was thenfiltered to remove triethylamine hydrochloride and concentrated todryness. The residue was dissolved in EtOAc and washed with 5% HCl(1×100 mL), saturated NaHCO₃ (2×200 mL), dried over MgSO4, and thesolvents were removed to dryness. The crude oil was chromatographedthrough 1.4 L of SiO₂ (CH₂Cl₂:Hexanes, 1:1). The product was isolated asa white amorphous solid after removal of the solvents. Yield 33.0 g,92%. ¹H NMR (500 MHz, CD₂Cl₂, 25° C.) δ 0.88 (t, 3H), 1.33 (m, 4H), 1.43(m, 2H), 1.74 (m, 2H), 2.41 (s, 3H), 3.91 (t, 2H), 4.09 (t, 2H), 4.31(t, 2H), 6.68 (d, 2H), 6.77 (d, 2H), 7.03 (m, 4H), 7.34 (d, 2H), 7.46(d, 2H), 7.50 (d, 2H), 7.63 (d, 2H), 7.78 (d, 2H).

Example 5 Synthesis of9-(4-Hexyloxyphenyl)-9′-(4-(4-(2-ethoxy)-benzaldehyde)phenyl)-fluorene(7)

A stirred DMF solution (15 mL) containing the tosylated fluorene 5 (4.30g, 5.76 mmol), 4-hydroxybenzaldehyde (1.10 g, 8.63 mmol), and K₂CO₃(1.70 g, 12.0 mmol) was heated at 80° C. The tosylated fluorene wasconsumed after 2 h as evidenced by TLC (EtOAc:Hexanes, 1:9). Thereaction was cooled and H₂O (100 mL) followed by EtOAc (150 mL) andlayers were separated after the contents were transferred to aseparatory funnel. The organic layer was washed with 5% NaOH (2×100 mL),brine (1×100 mL), and dried over MgSO₄. The solvents were removed todryness to give a light-pink colored solid (3.80 g). The product wasadsorbed on to SiO₂ and chromatographed through SiO2 (EtOAc: Hexanes,gradient 1:20 to 1:9) and isolated as a white solid after removal of thesolvents. Yield 3.40 g, 77%. ¹H NMR (400 MHz, CD2Cl2, 25° C.) δ 0.87 (t,3H), 1.32 (m, 4H), 1.42 (m, 2H), 1.75 (m, 2H), 3.90 (t, 2H), 4.31 (m,2H), 4.38 (m, 2H), 6.77 (d, 2H), 6.83 (d, 2H), 7.05 (m, 6H), 7.49 (m,4H), 7.63 (d, 2H), 7.83 (d, 2H), 9.87 (s, 1H).

TABLE 1 Preparation of Pendant Benzaldehyde Polyfluorene Compound F8-HOFALD- POZ- PCy- Et₄NOH bisborate BR₂ Br₂ Pd(OAc)₂ Biphen (20% Aq) H₂0PhCH₃ MW 530.35 762.44 473.20 224.51 410.53 147.26 50 mL mmol 2.41 1.810.6 0.04 0.13 12.07 mg 1278.1 1380.0 283.9 8.1 52.5 8887.1 8.89 g

Example 6 Preparation of Pendant Benzaldehyde Polyfluorene

A 150 ml three-neck flask with a nitrogen inlet to a bubbler and amagnetic stirrer was charged with all the monomers, PCy-Biphen andtoluene (45 mL). This solution is degassed with nitrogen for 5-10minutes then Pd(OAc)₂ is added using the remaining toluene to rinse anyPd(OAc)₂ adhering to the walls of the flask. Simultaneously in anaddition funnel fitted to the three-neck flask, the aqueous componentsare degassed with nitrogen. After at least 20 minutes of degassing, theaqueous components were added to the organic solution and the flask wasimmersed in a sand bath at 80° C. The biphasic reaction mixture washeated under a positive pressure of nitrogen for 20 hrs after whichpoint the solution was cooled to room temperature. The contents of thereaction vessel were transferred to a blender containing MeOH (500 mL)and blended for 5 min. The polymer was collected by filtration, washedwith methanol and dried under vacuum overnight. Yield 2.26g (55%). Gelpermeation chromatography indicated Mw=1.04×107 and Mn=4.73×106(Mw/Mw=2.19) relative to polystyrene standards.

Example 7 Preparation of Pendant Benzylamine Polyfluorene

The pendant benzaldehyde polyfluorene (0.500 g) was dissolved in toluene(100 mL) and treated with benzylamine (0.500 mL, 4.58 mmol). Thesolvents were removed under reduced pressure using a rotary evaporator.The addition and removal of fresh toluene (100 mL) was repeated twoadditional times. After the last removal of toluene, the polymer residuewas dissolved in THF (20 mL) and EtOH (2 mL) was added as a co-solvent.To this solution was added NaBH₄ (300 mg, 7.93 mmol) and the reactionmixture was stirred at room temperature for 2 hrs. The solution changedcolor from yellow to yellow-brown. The reaction mixture was treated withAcOH (20 drops) and stirring was continued until the evolution of gasessubsided. The solvents were removed and the polymeric residue wasdissolved in the minimum amount of toluene. The toluene solution waspoured into a blender containing MeOH (400 mL) causing the polymer toprecipitate from solution as a fine powder. The product was collected byfiltration and washed briefly with MeOH. The solid material wasdissolved in toluene (30 mL) and passed through a short column of SiO₂(25 mL) equilibrated with toluene. After eluting with toluene the firstmajor yellow fraction was collected, concentrated to 50 mL andprecipitated from MeOH (500 mL) in a blender as a fine powder. Thepolymer was collected by filtration and washed with MeOH. Dried invacuum at room temperature. Yield 320 mg.

Example 8 Preparation of Pendant 4-Methoxybenzylamine Polyfluorene

The pendant benzaldehyde polyfluorene (0.500 g) was dissolved in toluene(100 mL) and treated with 4-methoxybenzylamine (0.500 mL, 3.83 mmol).The solvents were removed under reduced pressure using a rotaryevaporator. The addition and removal of fresh toluene (100 mL) wasrepeated three additional times. After the last removal of toluene, thepolymer residue was dissolved in toluene (50 mL) and EtOH (5 mL) wasadded as a co-solvent. To this solution was added NaBH₄ (500 mg, 13.2mmol) and the reaction mixture was stirred at room temperature. After 20mins the solution changed color from yellow to yellow-brown. Thereaction mixture was heated at reflux for 1 h after which the solutioncooled to room temperature. The reaction mixture was treated with 80%EtOH (20 mL) and transferred to a blender containing MeOH (500 mL)causing the polymer to precipitate from solution as a fine powder. Theproduct was collected by filtration and washed briefly with MeOH anddried under vacuum at room temperature. The solid material (0.502 g) wasdissolved in 10% MeOH/CH₂Cl₂ (20 mL) and vacuum filtered through glassfiber filter paper into MeOH (500 mL) with stirring. The polymerprecipitated from solution as yellow stringy fibers and was collected byfiltration and washed with MeOH. Dried in vacuum at room temperature.Yield 446 mg.

Example 9 Preparation of Pendant Benzylalcohol Polyfluorene

The pendant benzaldehyde polyfluorene (0.500 g) was dissolved in 10%EtOH/Toluene (11 mL) and treated with NaBH₄ (250 mg, 6.60 mmol) and thereaction mixture was stirred at room temperature. After 20 mins thesolution changed color from yellow to yellow-brown. The reaction mixturewas heated at reflux for 1 h after which the solution cooled to roomtemperature. The reaction mixture was treated with AcOH (1 mL) drop wiseand stirring was continued until the evolution of gases subsided. Thecontents were transferred to a blender containing MeOH (500 mL) causingthe polymer to precipitate from solution. The product was collected byfiltration, washed briefly with MeOH and partially dried in air. Thesolid material was dissolved in 10% MeOH/CH₂Cl₂ (20 mL) and vacuumfiltered through glass fiber filter paper into MeOH (500 mL) withstirring. The polymer precipitated from solution as yellow-green stringyfibers and was collected by filtration and washed with MeOH. Dried invacuum at room temperature. Yield 219 mg.

Example 10 Synthesis9-(4-Hexyloxyphenyl)-9′-(4-(4-(2-ethoxy)-aminobenzene)phenyl)-fluorene(7a)

A stirred DMF solution (15 mL) containing the tosylated fluorene 5 (4.30g, 5.76 mmol), 4-hydroxy-acetanilide (8.63 mmol), and K₂CO₃ (1.70 g,12.0 mmol) are heated at 80° C. The progress of the reaction ismonitored by thin layer chromatography (TLC). The reaction is cooled andH₂O (100 mL) followed by EtOAc (150 mL) and layers are separated afterthe contents are transferred to a separatory funnel. The organic layeris washed with 5% NaOH (2×100 mL), brine (1×100 mL), and dried overMgSO₄. The solvents are removed to dryness to give the crude residue.The product is purified by column chromatography through SiO₂.

Example 11 Synthesis9-(4-Hexyloxyphenyl)-9′-(4-(4-(2-ethoxy)-aminomethylbenzene)phenyl)-fluorene(7b)

A stirred DMF solution (15 mL) containing the tosylated fluorene 5 (4.30g, 5.76 mmol), N-Boc-4-hydroxy-benzylamine (8.63 mmol), and K₂CO₃ (1.70g, 12.0 mmol) are heated at 80° C. The progress of the reaction ismonitored by thin layer chromatography (TLC). The reaction is cooled andH₂O (100 mL) followed by EtOAc (150 mL) and layers are separated afterthe contents are transferred to a separatory funnel. The organic layeris washed with 5% NaOH (2×100 mL), brine (1×100 mL), and dried overMgSO₄. The solvents are removed to dryness to give the crude residue.The product is purified by column chromatography through SiO₂. T

Example 12 Preparation of Pendant Benzylamine Polyfluorene

TABLE 2 Preparation of Pendant Benzylamine Polyfluorene Compound PCy-Et4NOH 8 7b 9 Pd(OAc)2 Biphen (20% Aq) H20 PhCH3 MW 530.35 763.47 473.20224.51 410.53 147.26 50 mL mmol 2.41 1.81 0.6 0.04 0.13 12.07 mg 1278.11381.8 283.9 8.1 52.5 8887.1 8.89 g

A 150 ml three-neck flask with a nitrogen inlet to a bubbler and amagnetic stirrer is charged with all the monomers, PCy-Biphen andtoluene (45 mL). This solution is degassed with nitrogen for 5-10minutes then Pd(OAc)₂ is added using the remaining toluene to rinse anyPd(OAc)₂ adhering to the walls of the flask. Simultaneously in anaddition funnel fitted to the three-neck flask, the aqueous componentsare degassed with nitrogen. After at least 20 minutes of degassing, theaqueous components are added to the organic solution and the flask isimmersed in a sand bath at 80° C. The biphasic reaction mixture isheated under a positive pressure of nitrogen for 20 hrs after whichpoint the solution is cooled to room temperature. The contents of thereaction vessel are transferred to a blender containing MeOH (500 mL)and blended for 5 min. The polymer is collected by filtration, washedwith methanol and dried under vacuum overnight.

Example 13 Preparation of Pendant Secondary Benzylamine Polyfluorene

The pendant benzylamine polyfluorene (0.500 g) is dissolved in toluene(100 mL) and treated with an benzaldehyde. The solvents are removedunder reduced pressure using a rotary evaporator. The addition andremoval of fresh tolulene (100 mL) is repeated two additional times.After the last removal of toluene, the polymer residue is dissolved inTHF (20 mL) and EtOH (2 mL) is added as a co-solvent. To this solutionis added NaBH₄ (300 mg, 7.93 mmol) and the reaction mixture is stirredat room temperature for 2 hrs. The reaction mixture is treated with AcOH(20 drops) and stirring is continued until the evolution of gasessubsided. The solvents are removed and the polymeric residue isdissolved in the minimum amount of toluene. The toluene solution ispoured into a blender containing MeOH (400 mL) causing the polymer toprecipitate from solution as a fine powder. The product is collected byfiltration and washed briefly with MeOH. The solid material is dissolvedin toluene (30 mL) and passed through a short column of SiO₂ (25 mL)equilibrated with toluene. After eluting with toluene the first majoryellow fraction is collected, concentrated to 50 mL and precipitatedfrom MeOH (500 mL) in a blender as a fine powder. The polymer iscollected by filtration and washed with MeOH. Dried in vacuum at roomtemperature.

Example 14 Preparation of Pendant Ir Complex Polyfluorene

The pendant benzylamine polyfluorene (0.500 g) is dissolved in toluene(100 mL) and treated with the aldehyde iridium complex Ir—CHO. Thesolvents are removed under reduced pressure using a rotary evaporator.The addition and removal of fresh tolulene (100 mL) is repeated threeadditional times. After the last removal of toluene, the polymer residueis dissolved in toluene (50 mL) and EtOH (5 mL) is added as aco-solvent. To this solution is added NaBH4 (500 mg, 13.2 mmol) and thereaction mixture is stirred at room temperature. The reaction mixture istreated with 80% EtOH (20 mL) and transferred to a blender containingMeOH (500 mL) causing the polymer to precipitate from solution. Theproduct is collected by filtration and washed briefly with MeOH anddried under vacuum at room temperature.

Example 15 Preparation of Ir—CHO

:A stirred DMF solution (15 mL) containing the4-(bromomethyl)-benzaldehyde (1.2 mmol), the2-(4-hydroxybenzoyl)-pyrrolo)Ir(piq)2 complex (1.0 mmol), and K₂CO₃(0.85 g, 6.0 mmol) are heated at 80° C. The progress of the reaction ismonitored by thin layer chromatography (TLC). The reaction is cooled andH₂O (100 mL) followed by EtOAc (150 mL) and layers are separated afterthe contents are transferred to a separatory funnel. The organic layeris washed with 5% NaOH (2×100 mL), brine (1×100 mL), and dried overMgSO₄. The solvents are removed to dryness to give the crude residue.The product is purified by column chromatography through SiO₂.

Equivalents

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The foregoingembodiments are therefore to be considered in all respects asillustrative rather than limiting on the invention described herein. Thescope of the invention is thus indicated by the appended claims ratherthan by the foregoing description, and all changes that come within themeaning and range of equivalency of the claims are therefore intended tobe embraced therein.

1. A polyfluorene comprising at least one structural group of formula V

wherein R⁶ is a group of formula VI

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof; and R¹¹ and R¹² takentogether form a substituted or unsubstituted monocyclic or bicyclicheteroaromatic ring; R¹³ is independently at each occurrence halo,nitro, hydroxy, amino, alkyl, aryl, arylalkyl, alkoxy, substitutedalkoxy, substituted alkyl, substituted aryl, or substituted arylalkyl;Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof; W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or acombination thereof; X′ is selected from a direct bond, alkylene,substituted alkylene, or combinations thereof; Y′ is alkylene,substituted alkylene, arylene, substituted arylene, oxaalkylene,substituted oxaalkylene, or a combination thereof; X″ is alkylidene,substituted alkylidene, or a combination thereof; Y″ is alkylidene,substituted alkylidene, arylidene, substituted arylidene, or acombination thereof, and p is 0, 1 or
 2. 2. A polyfluorene according toclaim 1 wherein Y′ is oxaalkylene, substituted oxaalkylene, or acombination thereof.
 3. A polyfluorene according to claim 2 wherein Y′is


4. A polyfluorene according to claim 1 wherein R¹¹ and R¹² takentogether form a substituted or unsubstituted isoquinoline.
 5. Apolyfluorene according to claim 1 wherein X is a direct bond.
 6. Apolyfluorene according to claim 1 wherein R⁶ additionally comprises atleast one triarylamine group.
 7. A polyfluorene according to claim 6wherein the triarylamine group comprises at least one triarylaminesubstituted secondary amino group, triarylamine substituted imine group,or a combination thereof.
 8. A polyfluorenes according to claim 6wherein weight percentage of the group of formula VI to the triarylaminegroup is from about 0.5 to about 50 mol %.
 9. An organic optoelectronicdevice comprising a polymer having at least one structural group offormula V

wherein R⁶ is a group of formula VI

R³, R⁴ and R⁷ are independently hydrogen, alkyl, substituted alkyl, arylsubstituted aryl, and combinations thereof; and R¹¹ and R¹² takentogether form a substituted or unsubstituted monocyclic or bicyclicheteroaromatic ring; R¹³ is independently at each occurrence halo,nitro, hydroxy, amino, alkyl, aryl, arylalkyl, alkoxy, substitutedalkoxy, substituted alkyl, substituted aryl, or substituted arylalkyl;Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, or acombination thereof; W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or acombination thereof; X′ is selected from a direct bond, alkylene,substituted alkylene, or combinations thereof; Y′ is alkylene,substituted alkylene, arylene, substituted arylene, oxaalkylene,substituted oxaalkylene, or a combination thereof; X″ is alkylidene,substituted alkylidene, or a combination thereof; Y″ is alkylidene,substituted alkylidene, arylidene, substituted arylidene, or acombination thereof, and p is 0, 1 or
 2. 10. An organic optoelectronicdevice according to claim 9 wherein Y′ is oxaalkylene, substitutedoxaalkylene, or a combination thereof.
 11. An organic optoelectronicdevice according to claim 10 wherein Y′ is


12. An organic optoelectronic device according to claim 9 wherein R¹¹and R¹² taken together form a substituted or unsubstituted isoquinoline.13. An organic optoelectronic device according to claim 9 wherein R⁶additionally comprises at least one triarylamine group.
 14. An organicoptoelectronic device according to claim 13 wherein the triarylaminegroup is a substituted secondary amino group, triarylamine substitutedimine group, or a combination thereof.
 15. An organic optoelectronicdevice according to claim 13 wherein the at least one triarylamine groupis a compound of formula VII

wherein R″ and R′″ are independently hydrogen, alkyl, substituted alkyl,alkenyl, alkynyl, substituted alkenyl, substituted alkynyl, alkyloxy,substituted alkoxy, alkenoxy, alkynoxy, substituted alkenoxy,substituted alkynoxy, taken together a heterocyclic ring or acombination thereof; Ar⁶ and Ar⁷ are independently aryl, heteroaryl,substituted aryl, substituted heteroaryl, or a combination thereof; R′is an alkyl, substituted alkyl, alkenyl, alkynyl, substituted alkenyl,substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy, alkynoxy,substituted alkenoxy, substituted alkynoxy, or a combination thereof; Wis —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or a combination thereof; X′ isselected from a direct bond, alkylene, substituted alkylene, orcombinations thereof; Y′ is alkylene, substituted alkylene, arylene,substituted arylene, oxaalkylene, substituted oxaalkylene, or acombination thereof; X″ is alkylidene, substituted alkylidene, or acombination thereof; Y″ is alkylidene, substituted alkylidene,arylidene, substituted arylidene, or a combination thereof, and n is aninteger from 0 to
 4. 16. An organic optoelectronic device according toclaim 15 wherein Y′ is oxaalkylene, substituted oxaalkylene, or acombination thereof.
 17. An organic optoelectronic device according toclaim 16 wherein Y′ is


18. An organic optoelectronic device according to claim 13 wherein theat least one triarylamine group is a compound of formula VIII

wherein R′ is an alkyl, substituted alkyl, alkenyl, alkynyl, substitutedalkenyl, substituted alkynyl, alkyloxy, substituted alkoxy, alkenoxy,alkynoxy, substituted alkenoxy, substituted alkynoxy, or a combinationthereof; W is —X′—NH—Y′—, —X′—N═Y″—, —X″═N—Y′—, or a combinationthereof; X′ is selected from a direct bond, alkylene, substitutedalkylene, or combinations thereof; Y′ is alkylene, substituted alkylene,arylene, substituted arylene, oxaalkylene, substituted oxaalkylene, or acombination thereof; X″ is alkylidene, substituted alkylidene, or acombination thereof; Y″ is alkylidene, substituted alkylidene,arylidene, substituted arylidene, or a combination thereof, and n is aninteger from 0 to
 4. 19. An organic optoelectronic device according toclaim 18 wherein Y′ is oxaalkylene, substituted oxaalkylene, or acombination thereof.
 20. An organic optoelectronic device according toclaim 19 wherein Y′ is


21. An organic optoelectronic device according to claim 13 whereinweight percentage of the group of formula VI to the triarylamine groupis from about 0.5 to about 50 mol %.
 22. An organic optoelectronicdevice according to claim 9 comprising structural units of formula IX

wherein R⁷, R⁸ and R⁹ are independently hydrogen, alkyl, substitutedalkyl, arly substituted aryl, and combinations thereof; R¹¹ and R¹²taken together form a substituted or unsubstituted monocyclic orbicyclic heteroaromatic ring; R¹³ is independently at each occurrencehalo, nitro, hydroxy, amino, alkyl, aryl, arylalkyl, alkoxy, substitutedalkoxy, substituted alkyl, substituted aryl, or substituted arylalkyl;and Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl, ora combination thereof.